1. Field of the Invention
The present invention relates generally to switch devices for switching the positions of railway tracks in order for trains to move from one track to another. More particularly, the present invention relates to a cam bar of a railroad track switching machine that permits the switch machine to continue operating, even when a lock bar of the switch machine is not able to lock into its proper position.
2. Description of the Prior Art
A switch machine is commonly used to perform a switching operation of a train from one railroad track to another. The switch machine controls the switching operation by connections to the railroad tracks through a throw bar, lock bar, and point detector bar. The throw bar throws a pair of inner tracks, located between a pair of stock rails, from one track position to another. The lock bar locks the inner tracks after the throw bar has switched them into position. The point detector bar determines whether the inner tracks have moved to a proper position. If so, a point detector system indicates a "safe condition" to a local or remote operator.
Normally, an electric motor provides the switch machine with the power required to throw the inner tracks from one position to another. However, there are certain situations when utilizing the electric motor is not possible or less than favorable, such as when communication between the switch machine and a remote control location is lost or a failure inside the switch machine prevents normal operation. In such situations, a hand throw operation of the switch machine permits maintenance personnel to manually switch the tracks by throwing a hand throw switch.
Similar to a normal situation when the electric motor is used, the lock bar of the switch machine locks the position of the inner tracks after they have been thrown by the hand throw switch. Also, a hand throw arm is positioned in a latch stand and padlocked thereto in order to prevent unauthorized personnel from throwing the hand throw switch.
Switch machines and their associated railroad tracks are operated in very hostile environments. Commonly, hazards and damage to a switch machine and its tracks prevents them from operating normally. When an electric motor does not throw the inner tracks as requested by an operator, operational personnel may resort to hand throwing the tracks. However, if the switch machine or its tracks has been damage in a manner that prevents the lock bar from operating properly, completion of the hand throw operation may not be possible and the operation of trains through that vicinity will be tied up until the problem is fixed. This type of delay can result in costly financial losses for railroad operators and owners.
Therefore, it is the purpose of the present invention to provide a device that will permit a hand throw operation to be completed even when its lock bar does not properly lock its associated inner tracks into position. This device permits trains to pass through railroad tracks associated with the switch machine with the switch points otherwise secured until the problem can be corrected.
Accordingly, it is a primary object of the present invention to overcome the aforenoted problem associated with operating a railroad network when the lock bar of a switch machine is not operating properly.
Another object of the present invention is to provide an override provision of a switch machine for operating the throw bar to switch the railroad tracks even though the lock bar does not properly lock the tracks in position.
A further object of the present invention is to prevent a malfunction of the lock bar and its operation from interfering with the hand throw operation of manually throwing the railroad tracks.
Yet another object of the present invention is to prevent an indicator means of a switch machine from indicating a "safe condition" when the lock bar is not operational.
Still another object of the present invention is to provide an override provision of a switch machine when the lock bar is not operational, having the ability to automatically return to its normal operation once the problem with the lock bar has been cleared or fixed.